Parts of Ireland will bask in scorching temperatures of up to 28C on Thursday.
Met Eireann has forecast the hottest day of the year so far - and urged the public to take care in the sunshine.
The weather chiefs said the Solar UV index will be very high, but there is still a threat of thunderstorms in places.
A forecaster said: "Today will be a very warm day and the Solar UV index is very high, so do take care in the sunshine.
"It will be another dry and sunny day with the risk of isolated heavy or possibly thundery showers in the southwest.
"Top temperatures will reach of 22 to 28 degrees, warmest across Connacht and the mid-west, but a few degrees lower along eastern coastal fringes in moderate to fresh easterly onshore breezes."
A Status Yellow high-temperature warning will be in place on Thursday afternoon for six counties.
Galway, Mayo, Clare, Limerick, Kerry and Cork have been issued with the caution as temperatures look set to exceed 27C. The warning is valid between 1pm and 7pm on Thursday.
A forecaster said: "Status Yellow - High-Temperature warning for Galway, Mayo, Clare, Cork, Kerry and Limerick.
"Temperatures will be in excess of 27.0 degrees Celsius, during Thursday afternoon."
And it's going to be an extremely warm summers night with highs of 17C.
Ireland will remain mostly dry, apart from the odd shower.
"Tonight will be mostly dry with just the risk of an isolated shower in the southwest.
"It will be a mild and humid with lowest temperatures staying around 13 to 17 degrees in mainly moderate easterly breezes but fresh near coasts."
Friday will be as warm as 27C - despite there being a risk of thundery showers in the west.
Those heavy showers will make their way eastwards on Saturday, as parts of the country enjoy highs of 25C.
